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<a href="sched__task_8hpp.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a id="l00001" name="l00001"></a><span class="lineno">    1</span><span class="comment">/* Flow</span></div>
<div class="line"><a id="l00002" name="l00002"></a><span class="lineno">    2</span><span class="comment"> * Copyright 2023 Akamai Technologies, Inc.</span></div>
<div class="line"><a id="l00003" name="l00003"></a><span class="lineno">    3</span><span class="comment"> *</span></div>
<div class="line"><a id="l00004" name="l00004"></a><span class="lineno">    4</span><span class="comment"> * Licensed under the Apache License, Version 2.0 (the</span></div>
<div class="line"><a id="l00005" name="l00005"></a><span class="lineno">    5</span><span class="comment"> * &quot;License&quot;); you may not use this file except in</span></div>
<div class="line"><a id="l00006" name="l00006"></a><span class="lineno">    6</span><span class="comment"> * compliance with the License.  You may obtain a copy</span></div>
<div class="line"><a id="l00007" name="l00007"></a><span class="lineno">    7</span><span class="comment"> * of the License at</span></div>
<div class="line"><a id="l00008" name="l00008"></a><span class="lineno">    8</span><span class="comment"> *</span></div>
<div class="line"><a id="l00009" name="l00009"></a><span class="lineno">    9</span><span class="comment"> *   https://www.apache.org/licenses/LICENSE-2.0</span></div>
<div class="line"><a id="l00010" name="l00010"></a><span class="lineno">   10</span><span class="comment"> *</span></div>
<div class="line"><a id="l00011" name="l00011"></a><span class="lineno">   11</span><span class="comment"> * Unless required by applicable law or agreed to in</span></div>
<div class="line"><a id="l00012" name="l00012"></a><span class="lineno">   12</span><span class="comment"> * writing, software distributed under the License is</span></div>
<div class="line"><a id="l00013" name="l00013"></a><span class="lineno">   13</span><span class="comment"> * distributed on an &quot;AS IS&quot; BASIS, WITHOUT WARRANTIES OR</span></div>
<div class="line"><a id="l00014" name="l00014"></a><span class="lineno">   14</span><span class="comment"> * CONDITIONS OF ANY KIND, either express or implied.</span></div>
<div class="line"><a id="l00015" name="l00015"></a><span class="lineno">   15</span><span class="comment"> * See the License for the specific language governing</span></div>
<div class="line"><a id="l00016" name="l00016"></a><span class="lineno">   16</span><span class="comment"> * permissions and limitations under the License. */</span></div>
<div class="line"><a id="l00017" name="l00017"></a><span class="lineno">   17</span><span class="comment"></span> </div>
<div class="line"><a id="l00018" name="l00018"></a><span class="lineno">   18</span><span class="comment">/// @file</span></div>
<div class="line"><a id="l00019" name="l00019"></a><span class="lineno">   19</span><span class="comment"></span><span class="preprocessor">#pragma once</span></div>
<div class="line"><a id="l00020" name="l00020"></a><span class="lineno">   20</span> </div>
<div class="line"><a id="l00021" name="l00021"></a><span class="lineno">   21</span><span class="preprocessor">#include &quot;<a class="code" href="sched__task__fwd_8hpp.html">flow/util/sched_task_fwd.hpp</a>&quot;</span></div>
<div class="line"><a id="l00022" name="l00022"></a><span class="lineno">   22</span><span class="preprocessor">#include &quot;<a class="code" href="sched__task__handle__state_8hpp.html">flow/util/detail/sched_task_handle_state.hpp</a>&quot;</span></div>
<div class="line"><a id="l00023" name="l00023"></a><span class="lineno">   23</span><span class="preprocessor">#include &quot;<a class="code" href="log_8hpp.html">flow/log/log.hpp</a>&quot;</span></div>
<div class="line"><a id="l00024" name="l00024"></a><span class="lineno">   24</span><span class="preprocessor">#include &quot;flow/error/error.hpp&quot;</span></div>
<div class="line"><a id="l00025" name="l00025"></a><span class="lineno">   25</span> </div>
<div class="line"><a id="l00026" name="l00026"></a><span class="lineno">   26</span><span class="keyword">namespace </span><a class="code hl_namespace" href="namespaceflow_1_1util.html">flow::util</a></div>
<div class="line"><a id="l00027" name="l00027"></a><span class="lineno">   27</span>{</div>
<div class="line"><a id="l00028" name="l00028"></a><span class="lineno">   28</span> </div>
<div class="line"><a id="l00029" name="l00029"></a><span class="lineno">   29</span><span class="comment">// Free functions: in *_fwd.hpp.</span></div>
<div class="line"><a id="l00030" name="l00030"></a><span class="lineno">   30</span> </div>
<div class="line"><a id="l00031" name="l00031"></a><span class="lineno">   31</span><span class="comment">// Template implementations.</span></div>
<div class="line"><a id="l00032" name="l00032"></a><span class="lineno">   32</span> </div>
<div class="line"><a id="l00033" name="l00033"></a><span class="lineno">   33</span><span class="keyword">template</span>&lt;<span class="keyword">typename</span> Scheduled_task_handler&gt;</div>
<div class="line"><a id="l00034" name="l00034"></a><span class="lineno"><a class="line" href="namespaceflow_1_1util.html#a74d4a66fb00055be4e1bd6ee98e04667">   34</a></span><a class="code hl_typedef" href="namespaceflow_1_1util.html#aa0d10f5a906b3229f48979aa43e9ff7e">Scheduled_task_handle</a> <a class="code hl_function" href="namespaceflow_1_1util.html#a74d4a66fb00055be4e1bd6ee98e04667">schedule_task_from_now</a>(<a class="code hl_class" href="classflow_1_1log_1_1Logger.html">log::Logger</a>* logger_ptr,</div>
<div class="line"><a id="l00035" name="l00035"></a><span class="lineno">   35</span>                                             <span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a48799f1263cdeedec125be51a3db2b79">Fine_duration</a>&amp; from_now, <span class="keywordtype">bool</span> single_threaded,</div>
<div class="line"><a id="l00036" name="l00036"></a><span class="lineno">   36</span>                                             <a class="code hl_typedef" href="namespaceflow_1_1util.html#ac3e89a8a271b0ddc76ac2a0ce488dea4">Task_engine</a>* task_engine,</div>
<div class="line"><a id="l00037" name="l00037"></a><span class="lineno">   37</span>                                             Scheduled_task_handler&amp;&amp; task_body_moved)</div>
<div class="line"><a id="l00038" name="l00038"></a><span class="lineno">   38</span>{</div>
<div class="line"><a id="l00039" name="l00039"></a><span class="lineno">   39</span>  <span class="keyword">using </span>boost::chrono::round;</div>
<div class="line"><a id="l00040" name="l00040"></a><span class="lineno">   40</span>  <span class="keyword">using </span>boost::chrono::milliseconds;</div>
<div class="line"><a id="l00041" name="l00041"></a><span class="lineno">   41</span>  <span class="keyword">using </span><a class="code hl_class" href="classboost_1_1system_1_1system__error.html">boost::system::system_error</a>;</div>
<div class="line"><a id="l00042" name="l00042"></a><span class="lineno">   42</span>  <span class="keyword">using </span>boost::asio::bind_executor;</div>
<div class="line"><a id="l00043" name="l00043"></a><span class="lineno">   43</span>  <span class="keyword">using </span>boost::asio::get_associated_executor;</div>
<div class="line"><a id="l00044" name="l00044"></a><span class="lineno">   44</span>  <span class="keyword">using </span>boost::asio::post;</div>
<div class="line"><a id="l00045" name="l00045"></a><span class="lineno">   45</span> </div>
<div class="line"><a id="l00046" name="l00046"></a><span class="lineno">   46</span>  <a class="code hl_define" href="log_8hpp.html#ae4b5d4fdd2eb052615620879dd74af95">FLOW_LOG_SET_CONTEXT</a>(logger_ptr, Flow_log_component::S_UTIL);</div>
<div class="line"><a id="l00047" name="l00047"></a><span class="lineno">   47</span> </div>
<div class="line"><a id="l00048" name="l00048"></a><span class="lineno">   48</span>  <span class="comment">// See schedule_task_from_now() doc header for philosophical intro to what we are doing here: the context. Then read:</span></div>
<div class="line"><a id="l00049" name="l00049"></a><span class="lineno">   49</span> </div>
<div class="line"><a id="l00050" name="l00050"></a><span class="lineno">   50</span>  <span class="keyword">const</span> <span class="keyword">auto</span> task_id = <a class="code hl_function" href="classflow_1_1util_1_1Unique__id__holder.html#a50489177a7731618ca130468c3872748">Unique_id_holder::create_unique_id</a>();</div>
<div class="line"><a id="l00051" name="l00051"></a><span class="lineno">   51</span> </div>
<div class="line"><a id="l00052" name="l00052"></a><span class="lineno">   52</span>  <span class="comment">/* Shove all the state here, which is a ref-counted pointer around this simple struct.</span></div>
<div class="line"><a id="l00053" name="l00053"></a><span class="lineno">   53</span><span class="comment">   * Because we copy that ref-counted pointer into any lambda/closure we schedule, the state -- including the Timer</span></div>
<div class="line"><a id="l00054" name="l00054"></a><span class="lineno">   54</span><span class="comment">   * itself! -- will continue existing until none of *our* code needs it, at which point ref-count=0, and it is all</span></div>
<div class="line"><a id="l00055" name="l00055"></a><span class="lineno">   55</span><span class="comment">   * destroyed automatically.</span></div>
<div class="line"><a id="l00056" name="l00056"></a><span class="lineno">   56</span><span class="comment">   *</span></div>
<div class="line"><a id="l00057" name="l00057"></a><span class="lineno">   57</span><span class="comment">   * In addition, though, we return (in opaque fashion) a copy of this pointer in the return value of the present</span></div>
<div class="line"><a id="l00058" name="l00058"></a><span class="lineno">   58</span><span class="comment">   * function.  The life-time can thus be extended by the user (not that they need to worry about that internal</span></div>
<div class="line"><a id="l00059" name="l00059"></a><span class="lineno">   59</span><span class="comment">   * detail).  This is all trivially safe -- it exists until it doesn&#39;t need to, automatically -- but is there a</span></div>
<div class="line"><a id="l00060" name="l00060"></a><span class="lineno">   60</span><span class="comment">   * potential for wasted memory?  Answer: Not really; in addition to the struct being fairly light-weight, there&#39;s no</span></div>
<div class="line"><a id="l00061" name="l00061"></a><span class="lineno">   61</span><span class="comment">   * reason for user to keep a copy of this handle once the task has fired, or they&#39;ve had to cancel it.</span></div>
<div class="line"><a id="l00062" name="l00062"></a><span class="lineno">   62</span><span class="comment">   *</span></div>
<div class="line"><a id="l00063" name="l00063"></a><span class="lineno">   63</span><span class="comment">   * ### IMPORTANT SUBTLETY REGARDING THE SAVED LAMBDA IN task-&gt;m_body (LAST ARG TO CTOR) ###</span></div>
<div class="line"><a id="l00064" name="l00064"></a><span class="lineno">   64</span><span class="comment">   * Why save a wrapper function around task_body_moved (could just set m_body = task_body_moved), and</span></div>
<div class="line"><a id="l00065" name="l00065"></a><span class="lineno">   65</span><span class="comment">   * why not just execute m_body(&lt;true or false&gt;) synchronously from within the async_wait() handler below or</span></div>
<div class="line"><a id="l00066" name="l00066"></a><span class="lineno">   66</span><span class="comment">   * the handler post()ed by scheduled_task_short_fire(), and moreover why the strange-looking</span></div>
<div class="line"><a id="l00067" name="l00067"></a><span class="lineno">   67</span><span class="comment">   * get_associated_executor()/bind_executor() thing (could just post() task_body)?  Answer:</span></div>
<div class="line"><a id="l00068" name="l00068"></a><span class="lineno">   68</span><span class="comment">   *</span></div>
<div class="line"><a id="l00069" name="l00069"></a><span class="lineno">   69</span><span class="comment">   * For that matter, every other API as of this writing seems to take a concrete type, a Function&lt;&gt;, for callbacks --</span></div>
<div class="line"><a id="l00070" name="l00070"></a><span class="lineno">   70</span><span class="comment">   * avoiding templates -- but we take a template-param-typed arg.  Why?  Answer(s):</span></div>
<div class="line"><a id="l00071" name="l00071"></a><span class="lineno">   71</span><span class="comment">   *</span></div>
<div class="line"><a id="l00072" name="l00072"></a><span class="lineno">   72</span><span class="comment">   * schedule_task_from_now() is, essentially, a boost.asio extension that is akin to its various async_*() methods</span></div>
<div class="line"><a id="l00073" name="l00073"></a><span class="lineno">   73</span><span class="comment">   * and free functions (like Timer::async_wait() itself), in that it takes a completion handler to execute async later.</span></div>
<div class="line"><a id="l00074" name="l00074"></a><span class="lineno">   74</span><span class="comment">   * As such there is the expectation that, if it&#39;s associated with a `strand`, it will execute from within that strand</span></div>
<div class="line"><a id="l00075" name="l00075"></a><span class="lineno">   75</span><span class="comment">   * (meaning non-concurrently with any other handlers also so-associated).  (More generally, a strand is an &quot;executor&quot;,</span></div>
<div class="line"><a id="l00076" name="l00076"></a><span class="lineno">   76</span><span class="comment">   * and one expects it to be executed through that &quot;executor.&quot;  See boost.asio docs, not that they&#39;re super-readable,</span></div>
<div class="line"><a id="l00077" name="l00077"></a><span class="lineno">   77</span><span class="comment">   * especially the link below.)</span></div>
<div class="line"><a id="l00078" name="l00078"></a><span class="lineno">   78</span><span class="comment">   *</span></div>
<div class="line"><a id="l00079" name="l00079"></a><span class="lineno">   79</span><span class="comment">   * Long story short, if they pass in X = boost::asio::bind_executor(some_strand, some_func), where some_func()</span></div>
<div class="line"><a id="l00080" name="l00080"></a><span class="lineno">   80</span><span class="comment">   * takes 1+ args, then to execute it on *task_engine we must do post(*task_engine, F), where F() takes no args</span></div>
<div class="line"><a id="l00081" name="l00081"></a><span class="lineno">   81</span><span class="comment">   * and invokes X(args...) in its { body }.  An easy mistake, and bug, is to simply call X(args...).</span></div>
<div class="line"><a id="l00082" name="l00082"></a><span class="lineno">   82</span><span class="comment">   * Per https://www.boost.org/doc/libs/1_77_0/doc/html/boost_asio/overview/core/strands.html</span></div>
<div class="line"><a id="l00083" name="l00083"></a><span class="lineno">   83</span><span class="comment">   * and https://www.boost.org/doc/libs/1_77_0/doc/html/boost_asio/reference/post.html, post(*task_engine, F) picks up</span></div>
<div class="line"><a id="l00084" name="l00084"></a><span class="lineno">   84</span><span class="comment">   * the association with some_strand via get_associated_executor() machinery, internally.  If we simply call</span></div>
<div class="line"><a id="l00085" name="l00085"></a><span class="lineno">   85</span><span class="comment">   * X(args...), then that association is ignored.  Therefore, when we post the wrapper F(), we have to associate F()</span></div>
<div class="line"><a id="l00086" name="l00086"></a><span class="lineno">   86</span><span class="comment">   * with some_strand.  This has 2 implications:</span></div>
<div class="line"><a id="l00087" name="l00087"></a><span class="lineno">   87</span><span class="comment">   *   - We have to post() the wrapper around X(), and we must re-bind that wrapper with X()&#39;s associated executor.</span></div>
<div class="line"><a id="l00088" name="l00088"></a><span class="lineno">   88</span><span class="comment">   *     This is done via bind_executor(get_associated_executor(X), F).</span></div>
<div class="line"><a id="l00089" name="l00089"></a><span class="lineno">   89</span><span class="comment">   *   - Even more subtly, if we took task_body_moved as a Function&lt;&gt; (Scheduled_task) and not a template arg</span></div>
<div class="line"><a id="l00090" name="l00090"></a><span class="lineno">   90</span><span class="comment">   *     Scheduled_task_handler, then their X will be beautifully auto-converted into a wrapping Function&lt;&gt;()...</span></div>
<div class="line"><a id="l00091" name="l00091"></a><span class="lineno">   91</span><span class="comment">   *     thus making get_associated_executor(Function&lt;&gt;(X)) return the default thing, and not some_strand.</span></div>
<div class="line"><a id="l00092" name="l00092"></a><span class="lineno">   92</span><span class="comment">   *     Hence we must carefully take their *actual* function object of indeterminate type, and extract the</span></div>
<div class="line"><a id="l00093" name="l00093"></a><span class="lineno">   93</span><span class="comment">   *     associated executor from *that*, not from Function&lt;&gt;(X).</span></div>
<div class="line"><a id="l00094" name="l00094"></a><span class="lineno">   94</span><span class="comment">   *</span></div>
<div class="line"><a id="l00095" name="l00095"></a><span class="lineno">   95</span><span class="comment">   * The rest flows from that.  We post() a very simple wrapper (with a bit of logging) through the same executor</span></div>
<div class="line"><a id="l00096" name="l00096"></a><span class="lineno">   96</span><span class="comment">   * (if any; if it&#39;s the default one then it still works) as the handler object they passed in.  I (ygoldfel) have</span></div>
<div class="line"><a id="l00097" name="l00097"></a><span class="lineno">   97</span><span class="comment">   * written so much text only because this is an easy mistake to make, and I have made it, causing a bug: it still</span></div>
<div class="line"><a id="l00098" name="l00098"></a><span class="lineno">   98</span><span class="comment">   * compiles and works... but not through the strand.  Tip: To directly check whether it worked,</span></div>
<div class="line"><a id="l00099" name="l00099"></a><span class="lineno">   99</span><span class="comment">   * `some_strand.running_in_this_thread()` must return true inside some_func().  Beats trying to force a thread-unsafe</span></div>
<div class="line"><a id="l00100" name="l00100"></a><span class="lineno">  100</span><span class="comment">   * situation and try to be satisfied when it doesn&#39;t occur (which is luck-based).</span></div>
<div class="line"><a id="l00101" name="l00101"></a><span class="lineno">  101</span><span class="comment">   *</span></div>
<div class="line"><a id="l00102" name="l00102"></a><span class="lineno">  102</span><span class="comment">   * P.S. I have verified, both in theory and in practice, that</span></div>
<div class="line"><a id="l00103" name="l00103"></a><span class="lineno">  103</span><span class="comment">   * `post(some_task_engine, bind_executor(get_associated_executor(F), F)` still executes through some_task_engine,</span></div>
<div class="line"><a id="l00104" name="l00104"></a><span class="lineno">  104</span><span class="comment">   * even when F is a vanilla lambda/function and not associated with any strand.  The theoretical reason it works</span></div>
<div class="line"><a id="l00105" name="l00105"></a><span class="lineno">  105</span><span class="comment">   * can be found in the post() doc link above, where it explains how precisely it invokes F() (both</span></div>
<div class="line"><a id="l00106" name="l00106"></a><span class="lineno">  106</span><span class="comment">   * some_task_engine, itself an executor, and g_a_e(F) are involved -- it works out; details omitted here).</span></div>
<div class="line"><a id="l00107" name="l00107"></a><span class="lineno">  107</span><span class="comment">   * The reason one might worry is that g_a_e(F), where F is non-strandy/vanilla, yields system_executor, which -- if</span></div>
<div class="line"><a id="l00108" name="l00108"></a><span class="lineno">  108</span><span class="comment">   * post()ed onto *directly* -- uses some unspecified thread/pool.  But together with post(some_task_engine),</span></div>
<div class="line"><a id="l00109" name="l00109"></a><span class="lineno">  109</span><span class="comment">   * it does work.</span></div>
<div class="line"><a id="l00110" name="l00110"></a><span class="lineno">  110</span><span class="comment">   *</span></div>
<div class="line"><a id="l00111" name="l00111"></a><span class="lineno">  111</span><span class="comment">   * P.P.S. Why not execute the async_wait()&#39;s completion handler below through g_a_e(task_body_moved)?  1, we have</span></div>
<div class="line"><a id="l00112" name="l00112"></a><span class="lineno">  112</span><span class="comment">   * our own algorithm for avoiding thread-unsafety and want to use *task_engine directly; it is less entropy-laden</span></div>
<div class="line"><a id="l00113" name="l00113"></a><span class="lineno">  113</span><span class="comment">   * to apply task_body_moved&#39;s associated executor only to task_body_moved itself (plus a bit of bracketing logging).</span></div>
<div class="line"><a id="l00114" name="l00114"></a><span class="lineno">  114</span><span class="comment">   * Whatever executor they associated task_body_moved with -- perhaps a strand, or something else -- has unknown</span></div>
<div class="line"><a id="l00115" name="l00115"></a><span class="lineno">  115</span><span class="comment">   * properties, and we have our own algorithm.</span></div>
<div class="line"><a id="l00116" name="l00116"></a><span class="lineno">  116</span><span class="comment">   * 2, then scheduled_task_short_fire() can just reuse task-&gt;m_body which already takes care of the</span></div>
<div class="line"><a id="l00117" name="l00117"></a><span class="lineno">  117</span><span class="comment">   * properly-executor-associated post()ing of task_body_moved.</span></div>
<div class="line"><a id="l00118" name="l00118"></a><span class="lineno">  118</span><span class="comment">   */</span></div>
<div class="line"><a id="l00119" name="l00119"></a><span class="lineno">  119</span>  <span class="keyword">auto</span> task = boost::make_shared&lt;Scheduled_task_handle_state&gt;</div>
<div class="line"><a id="l00120" name="l00120"></a><span class="lineno">  120</span>                (task_id, single_threaded, task_engine, [task_id, get_logger, get_log_component,</div>
<div class="line"><a id="l00121" name="l00121"></a><span class="lineno">  121</span>                                                         task_engine,</div>
<div class="line"><a id="l00122" name="l00122"></a><span class="lineno">  122</span>                                                         task_body = std::move(task_body_moved)]</div>
<div class="line"><a id="l00123" name="l00123"></a><span class="lineno">  123</span>                                                          (<span class="keywordtype">bool</span> short_fire) <span class="keyword">mutable</span></div>
<div class="line"><a id="l00124" name="l00124"></a><span class="lineno">  124</span>  {</div>
<div class="line"><a id="l00125" name="l00125"></a><span class="lineno">  125</span>    <span class="comment">// Not safe to rely on L-&gt;R arg evaluation below; get this 1st, when we know task_body hasn&#39;t been move()d.</span></div>
<div class="line"><a id="l00126" name="l00126"></a><span class="lineno">  126</span>    <span class="keyword">const</span> <span class="keyword">auto</span> executor = get_associated_executor(task_body); <span class="comment">// Usually system_executor (vanilla) or a strand.</span></div>
<div class="line"><a id="l00127" name="l00127"></a><span class="lineno">  127</span>    post(*task_engine,</div>
<div class="line"><a id="l00128" name="l00128"></a><span class="lineno">  128</span>         bind_executor(executor, [get_logger, get_log_component, task_id,</div>
<div class="line"><a id="l00129" name="l00129"></a><span class="lineno">  129</span>                                  task_body = std::move(task_body), short_fire]()</div>
<div class="line"><a id="l00130" name="l00130"></a><span class="lineno">  130</span>    {</div>
<div class="line"><a id="l00131" name="l00131"></a><span class="lineno">  131</span>      <a class="code hl_define" href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a>(<span class="stringliteral">&quot;Scheduled task [&quot;</span> &lt;&lt; task_id &lt;&lt;<span class="stringliteral">&quot;]: Body starting; short-fired? = [&quot;</span> &lt;&lt; short_fire &lt;&lt; <span class="stringliteral">&quot;].&quot;</span>);</div>
<div class="line"><a id="l00132" name="l00132"></a><span class="lineno">  132</span>      task_body(short_fire); <span class="comment">// NOTE: Might throw.</span></div>
<div class="line"><a id="l00133" name="l00133"></a><span class="lineno">  133</span>      <a class="code hl_define" href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a>(<span class="stringliteral">&quot;Scheduled task [&quot;</span> &lt;&lt; task_id &lt;&lt;<span class="stringliteral">&quot;]: Body finished without throwing exception.&quot;</span>);</div>
<div class="line"><a id="l00134" name="l00134"></a><span class="lineno">  134</span>    }));</div>
<div class="line"><a id="l00135" name="l00135"></a><span class="lineno">  135</span>  });</div>
<div class="line"><a id="l00136" name="l00136"></a><span class="lineno">  136</span>  <span class="comment">// task_body_moved is now potentially destroyed after move().</span></div>
<div class="line"><a id="l00137" name="l00137"></a><span class="lineno">  137</span> </div>
<div class="line"><a id="l00138" name="l00138"></a><span class="lineno">  138</span>  <span class="comment">// To be clear: If we want user&#39;s handler executed (below, or when short-firing) -- just call task-&gt;m_body(...).</span></div>
<div class="line"><a id="l00139" name="l00139"></a><span class="lineno">  139</span> </div>
<div class="line"><a id="l00140" name="l00140"></a><span class="lineno">  140</span>  <span class="keyword">auto</span>&amp; timer = task-&gt;m_timer;</div>
<div class="line"><a id="l00141" name="l00141"></a><span class="lineno">  141</span> </div>
<div class="line"><a id="l00142" name="l00142"></a><span class="lineno">  142</span>  <a class="code hl_define" href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a>(<span class="stringliteral">&quot;Scheduling task [&quot;</span> &lt;&lt; task-&gt;m_id &lt;&lt; <span class="stringliteral">&quot;] &quot;</span></div>
<div class="line"><a id="l00143" name="l00143"></a><span class="lineno">  143</span>                 <span class="stringliteral">&quot;to fire in [&quot;</span> &lt;&lt; round&lt;milliseconds&gt;(from_now) &lt;&lt; <span class="stringliteral">&quot;]; &quot;</span></div>
<div class="line"><a id="l00144" name="l00144"></a><span class="lineno">  144</span>                 <span class="stringliteral">&quot;task engine [&quot;</span> &lt;&lt; <span class="keyword">static_cast&lt;</span><span class="keywordtype">void</span>*<span class="keyword">&gt;</span>(task_engine) &lt;&lt; <span class="stringliteral">&quot;]; &quot;</span></div>
<div class="line"><a id="l00145" name="l00145"></a><span class="lineno">  145</span>                 <span class="stringliteral">&quot;single-threaded optimizations applicable? = [&quot;</span> &lt;&lt; single_threaded &lt;&lt; <span class="stringliteral">&quot;].&quot;</span>);</div>
<div class="line"><a id="l00146" name="l00146"></a><span class="lineno">  146</span> </div>
<div class="line"><a id="l00147" name="l00147"></a><span class="lineno">  147</span>  timer.expires_after(from_now);</div>
<div class="line"><a id="l00148" name="l00148"></a><span class="lineno">  148</span> </div>
<div class="line"><a id="l00149" name="l00149"></a><span class="lineno">  149</span>  <span class="comment">/* We&#39;ve prepared it all -- now kick off the state machine by scheduling an actual thing to run at the chosen time.</span></div>
<div class="line"><a id="l00150" name="l00150"></a><span class="lineno">  150</span><span class="comment">   * From this point on, unless single_threaded, the mutex must be used when accessing m_timer, m_canceled, m_ired.</span></div>
<div class="line"><a id="l00151" name="l00151"></a><span class="lineno">  151</span><span class="comment">   *</span></div>
<div class="line"><a id="l00152" name="l00152"></a><span class="lineno">  152</span><span class="comment">   * We don&#39;t schedule user-supplied body itself but rather a wrapper lambda around that body.  This allows us to</span></div>
<div class="line"><a id="l00153" name="l00153"></a><span class="lineno">  153</span><span class="comment">   * avoid various corner cases and annoyances of Timer -- as explained at length in the</span></div>
<div class="line"><a id="l00154" name="l00154"></a><span class="lineno">  154</span><span class="comment">   * present function&#39;s doc header. */</span></div>
<div class="line"><a id="l00155" name="l00155"></a><span class="lineno">  155</span>  timer.async_wait([get_logger, get_log_component, task](<span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">Error_code</a>&amp; sys_err_code)</div>
<div class="line"><a id="l00156" name="l00156"></a><span class="lineno">  156</span>  {</div>
<div class="line"><a id="l00157" name="l00157"></a><span class="lineno">  157</span>    <span class="keyword">const</span> <span class="keywordtype">bool</span> single_threaded = !task-&gt;m_mutex_unless_single_threaded;</div>
<div class="line"><a id="l00158" name="l00158"></a><span class="lineno">  158</span> </div>
<div class="line"><a id="l00159" name="l00159"></a><span class="lineno">  159</span>    <span class="comment">/* operation_aborted only occurs due to m_timer.cancel().  Under our semantics, the only way the latter</span></div>
<div class="line"><a id="l00160" name="l00160"></a><span class="lineno">  160</span><span class="comment">     * happens is if WE INTERNALLY do that, and the only reason we do that is if user did</span></div>
<div class="line"><a id="l00161" name="l00161"></a><span class="lineno">  161</span><span class="comment">     * scheduled_task_cancel() or scheduled_task_short_fire().</span></div>
<div class="line"><a id="l00162" name="l00162"></a><span class="lineno">  162</span><span class="comment">     *   - cancel case: They&#39;ve set m_canceled = true, so below code will detect it and return without m_body() call.</span></div>
<div class="line"><a id="l00163" name="l00163"></a><span class="lineno">  163</span><span class="comment">     *   - short-fire case: They&#39;ve set m_fired = true and posted m_body() call manually, so below code will similarly</span></div>
<div class="line"><a id="l00164" name="l00164"></a><span class="lineno">  164</span><span class="comment">     *     detect it and return without m_body() call.</span></div>
<div class="line"><a id="l00165" name="l00165"></a><span class="lineno">  165</span><span class="comment">     *</span></div>
<div class="line"><a id="l00166" name="l00166"></a><span class="lineno">  166</span><span class="comment">     * Hence, operation_aborted is indeed possible, but we use m_fired and m_canceled to clearly record why it</span></div>
<div class="line"><a id="l00167" name="l00167"></a><span class="lineno">  167</span><span class="comment">     * happened.  So, we simply allow operation_aborted but subsequently ignore whether it happened.  (The most we</span></div>
<div class="line"><a id="l00168" name="l00168"></a><span class="lineno">  168</span><span class="comment">     * could do is a sanity-check that if operation_aborted then m_fired or m_canceled must be true.) */</span></div>
<div class="line"><a id="l00169" name="l00169"></a><span class="lineno">  169</span> </div>
<div class="line"><a id="l00170" name="l00170"></a><span class="lineno">  170</span><span class="preprocessor">#ifndef NDEBUG </span><span class="comment">// The aforementioned sanity check.</span></div>
<div class="line"><a id="l00171" name="l00171"></a><span class="lineno">  171</span>    <span class="keywordflow">if</span> (sys_err_code == boost::asio::error::operation_aborted)</div>
<div class="line"><a id="l00172" name="l00172"></a><span class="lineno">  172</span>    {</div>
<div class="line"><a id="l00173" name="l00173"></a><span class="lineno">  173</span>      <span class="keywordflow">if</span> (single_threaded)</div>
<div class="line"><a id="l00174" name="l00174"></a><span class="lineno">  174</span>      {</div>
<div class="line"><a id="l00175" name="l00175"></a><span class="lineno">  175</span>        assert(task-&gt;m_fired != task-&gt;m_canceled); <span class="comment">// I.e., exactly one of them must be true.</span></div>
<div class="line"><a id="l00176" name="l00176"></a><span class="lineno">  176</span>      }</div>
<div class="line"><a id="l00177" name="l00177"></a><span class="lineno">  177</span>      <span class="keywordflow">else</span></div>
<div class="line"><a id="l00178" name="l00178"></a><span class="lineno">  178</span>      {</div>
<div class="line"><a id="l00179" name="l00179"></a><span class="lineno">  179</span>        <a class="code hl_typedef" href="namespaceflow_1_1util.html#a5d2247b715da63e4b960909561b90ae7">Lock_guard&lt;Mutex_non_recursive&gt;</a> lock(*task-&gt;m_mutex_unless_single_threaded);</div>
<div class="line"><a id="l00180" name="l00180"></a><span class="lineno">  180</span>        assert(task-&gt;m_fired != task-&gt;m_canceled);</div>
<div class="line"><a id="l00181" name="l00181"></a><span class="lineno">  181</span>      }</div>
<div class="line"><a id="l00182" name="l00182"></a><span class="lineno">  182</span>    }</div>
<div class="line"><a id="l00183" name="l00183"></a><span class="lineno">  183</span><span class="preprocessor">#endif</span></div>
<div class="line"><a id="l00184" name="l00184"></a><span class="lineno">  184</span> </div>
<div class="line"><a id="l00185" name="l00185"></a><span class="lineno">  185</span>    <span class="keywordflow">if</span> (sys_err_code &amp;&amp; (sys_err_code != boost::asio::error::operation_aborted)) <span class="comment">// As noted, ignore _aborted case now.</span></div>
<div class="line"><a id="l00186" name="l00186"></a><span class="lineno">  186</span>    {</div>
<div class="line"><a id="l00187" name="l00187"></a><span class="lineno">  187</span>      <a class="code hl_define" href="error_2error_8hpp.html#a019ee6e90802e444572dd78d312d6e23">FLOW_ERROR_SYS_ERROR_LOG_WARNING</a>();</div>
<div class="line"><a id="l00188" name="l00188"></a><span class="lineno">  188</span>      <a class="code hl_define" href="log_8hpp.html#a626c7dc4d3b4dc0b32a8aac8624d66bc">FLOW_LOG_WARNING</a>(<span class="stringliteral">&quot;Timer system error; just logged; totally unexpected; pretending it fired normally.&quot;</span>);</div>
<div class="line"><a id="l00189" name="l00189"></a><span class="lineno">  189</span>      <span class="comment">/* Again, this is totally unexpected.  Could throw here, but pretending it fired seems less explosive and</span></div>
<div class="line"><a id="l00190" name="l00190"></a><span class="lineno">  190</span><span class="comment">       * entropy-laden and might work out somehow.  Regardless, this is no-man&#39;s-land and a best effort. */</span></div>
<div class="line"><a id="l00191" name="l00191"></a><span class="lineno">  191</span>    }</div>
<div class="line"><a id="l00192" name="l00192"></a><span class="lineno">  192</span> </div>
<div class="line"><a id="l00193" name="l00193"></a><span class="lineno">  193</span>    <span class="comment">/* OK, it fired legitimately -- but if we marked it as already short-fired or canceled then we just NOOP.</span></div>
<div class="line"><a id="l00194" name="l00194"></a><span class="lineno">  194</span><span class="comment">     * This helper checks whether we should NOOP or actually run m_body().  Pre-condition: Thread-safe to touch *task.</span></div>
<div class="line"><a id="l00195" name="l00195"></a><span class="lineno">  195</span><span class="comment">     * It&#39;s a function due to the single_threaded dichotomy just below.  Otherwise it&#39;d just be direct inline code. */</span></div>
<div class="line"><a id="l00196" name="l00196"></a><span class="lineno">  196</span>    <span class="keyword">auto</span> should_fire = [&amp;]() -&gt; <span class="keywordtype">bool</span> <span class="comment">// [&amp;] meaning this can only be called synchronously within current function.</span></div>
<div class="line"><a id="l00197" name="l00197"></a><span class="lineno">  197</span>    {</div>
<div class="line"><a id="l00198" name="l00198"></a><span class="lineno">  198</span>      <span class="keywordflow">if</span> (task-&gt;m_fired)</div>
<div class="line"><a id="l00199" name="l00199"></a><span class="lineno">  199</span>      {</div>
<div class="line"><a id="l00200" name="l00200"></a><span class="lineno">  200</span>        <a class="code hl_define" href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a>(<span class="stringliteral">&quot;Scheduled task [&quot;</span> &lt;&lt; task-&gt;m_id &lt;&lt; <span class="stringliteral">&quot;] native timer fired (could be due to cancel() call), &quot;</span></div>
<div class="line"><a id="l00201" name="l00201"></a><span class="lineno">  201</span>                       <span class="stringliteral">&quot;but user handler already began executing earlier.  Done.&quot;</span>);</div>
<div class="line"><a id="l00202" name="l00202"></a><span class="lineno">  202</span>        <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
<div class="line"><a id="l00203" name="l00203"></a><span class="lineno">  203</span>      }</div>
<div class="line"><a id="l00204" name="l00204"></a><span class="lineno">  204</span>      <span class="comment">// else</span></div>
<div class="line"><a id="l00205" name="l00205"></a><span class="lineno">  205</span>      <span class="keywordflow">if</span> (task-&gt;m_canceled)</div>
<div class="line"><a id="l00206" name="l00206"></a><span class="lineno">  206</span>      {</div>
<div class="line"><a id="l00207" name="l00207"></a><span class="lineno">  207</span>        <a class="code hl_define" href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a>(<span class="stringliteral">&quot;Scheduled task [&quot;</span> &lt;&lt; task-&gt;m_id &lt;&lt; <span class="stringliteral">&quot;] native timer fired (could be due to cancel() call), &quot;</span></div>
<div class="line"><a id="l00208" name="l00208"></a><span class="lineno">  208</span>                       <span class="stringliteral">&quot;but task was already canceled earlier.  Done.&quot;</span>);</div>
<div class="line"><a id="l00209" name="l00209"></a><span class="lineno">  209</span>        <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
<div class="line"><a id="l00210" name="l00210"></a><span class="lineno">  210</span>      }</div>
<div class="line"><a id="l00211" name="l00211"></a><span class="lineno">  211</span>      <span class="comment">// else</span></div>
<div class="line"><a id="l00212" name="l00212"></a><span class="lineno">  212</span> </div>
<div class="line"><a id="l00213" name="l00213"></a><span class="lineno">  213</span>      <a class="code hl_define" href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a>(<span class="stringliteral">&quot;Scheduled task [&quot;</span> &lt;&lt; task-&gt;m_id &lt;&lt; <span class="stringliteral">&quot;] native timer fired (could be due to cancel() call), &quot;</span></div>
<div class="line"><a id="l00214" name="l00214"></a><span class="lineno">  214</span>                     <span class="stringliteral">&quot;and nothing has fired or canceled task already.  Proceeding with task (through post()).&quot;</span>);</div>
<div class="line"><a id="l00215" name="l00215"></a><span class="lineno">  215</span> </div>
<div class="line"><a id="l00216" name="l00216"></a><span class="lineno">  216</span>      task-&gt;m_fired = <span class="keyword">true</span>;</div>
<div class="line"><a id="l00217" name="l00217"></a><span class="lineno">  217</span>      <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
<div class="line"><a id="l00218" name="l00218"></a><span class="lineno">  218</span>    }; <span class="comment">// should_fire =</span></div>
<div class="line"><a id="l00219" name="l00219"></a><span class="lineno">  219</span> </div>
<div class="line"><a id="l00220" name="l00220"></a><span class="lineno">  220</span>    <span class="keywordtype">bool</span> noop;</div>
<div class="line"><a id="l00221" name="l00221"></a><span class="lineno">  221</span>    <span class="keywordflow">if</span> (single_threaded) <span class="comment">// Single-threaded =&gt; pre-condition is trivially true.  Else guarantee the pre-condition.</span></div>
<div class="line"><a id="l00222" name="l00222"></a><span class="lineno">  222</span>    {</div>
<div class="line"><a id="l00223" name="l00223"></a><span class="lineno">  223</span>      noop = !should_fire();</div>
<div class="line"><a id="l00224" name="l00224"></a><span class="lineno">  224</span>    }</div>
<div class="line"><a id="l00225" name="l00225"></a><span class="lineno">  225</span>    <span class="keywordflow">else</span></div>
<div class="line"><a id="l00226" name="l00226"></a><span class="lineno">  226</span>    {</div>
<div class="line"><a id="l00227" name="l00227"></a><span class="lineno">  227</span>      <a class="code hl_typedef" href="namespaceflow_1_1util.html#a5d2247b715da63e4b960909561b90ae7">Lock_guard&lt;Mutex_non_recursive&gt;</a> lock(*task-&gt;m_mutex_unless_single_threaded);</div>
<div class="line"><a id="l00228" name="l00228"></a><span class="lineno">  228</span>      noop = !should_fire();</div>
<div class="line"><a id="l00229" name="l00229"></a><span class="lineno">  229</span>    }</div>
<div class="line"><a id="l00230" name="l00230"></a><span class="lineno">  230</span> </div>
<div class="line"><a id="l00231" name="l00231"></a><span class="lineno">  231</span>    <span class="keywordflow">if</span> (noop)</div>
<div class="line"><a id="l00232" name="l00232"></a><span class="lineno">  232</span>    {</div>
<div class="line"><a id="l00233" name="l00233"></a><span class="lineno">  233</span>      <span class="keywordflow">return</span>;</div>
<div class="line"><a id="l00234" name="l00234"></a><span class="lineno">  234</span>    }</div>
<div class="line"><a id="l00235" name="l00235"></a><span class="lineno">  235</span>    <span class="comment">// else</span></div>
<div class="line"><a id="l00236" name="l00236"></a><span class="lineno">  236</span> </div>
<div class="line"><a id="l00237" name="l00237"></a><span class="lineno">  237</span>    (task-&gt;m_body)(<span class="keyword">false</span>); <span class="comment">// false &lt;=&gt; Regular firing; did not short-circuit.</span></div>
<div class="line"><a id="l00238" name="l00238"></a><span class="lineno">  238</span>    <a class="code hl_define" href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a>(<span class="stringliteral">&quot;Scheduled task [&quot;</span> &lt;&lt; task-&gt;m_id &lt;&lt;<span class="stringliteral">&quot;]: Body-post()ing function finished.&quot;</span>);</div>
<div class="line"><a id="l00239" name="l00239"></a><span class="lineno">  239</span>  }); <span class="comment">// async_wait()</span></div>
<div class="line"><a id="l00240" name="l00240"></a><span class="lineno">  240</span> </div>
<div class="line"><a id="l00241" name="l00241"></a><span class="lineno">  241</span>  <span class="keywordflow">return</span> task; <span class="comment">// If they save a copy of this (which is optional) they can call scheduled_task_cancel(), etc., on it.</span></div>
<div class="line"><a id="l00242" name="l00242"></a><span class="lineno">  242</span>} <span class="comment">// schedule_task_from_now()</span></div>
<div class="line"><a id="l00243" name="l00243"></a><span class="lineno">  243</span> </div>
<div class="line"><a id="l00244" name="l00244"></a><span class="lineno">  244</span><span class="keyword">template</span>&lt;<span class="keyword">typename</span> Scheduled_task_handler&gt;</div>
<div class="line"><a id="l00245" name="l00245"></a><span class="lineno"><a class="line" href="namespaceflow_1_1util.html#aad8c8f7335eb892350dc386cb4be397e">  245</a></span><a class="code hl_typedef" href="namespaceflow_1_1util.html#aa0d10f5a906b3229f48979aa43e9ff7e">Scheduled_task_handle</a> <a class="code hl_function" href="namespaceflow_1_1util.html#aad8c8f7335eb892350dc386cb4be397e">schedule_task_at</a>(<a class="code hl_class" href="classflow_1_1log_1_1Logger.html">log::Logger</a>* logger_ptr,</div>
<div class="line"><a id="l00246" name="l00246"></a><span class="lineno">  246</span>                                       <span class="keyword">const</span> <a class="code hl_typedef" href="namespaceflow.html#a9d9cc2eeb10d398cff5591d446b763b8">Fine_time_pt</a>&amp; at, <span class="keywordtype">bool</span> single_threaded,</div>
<div class="line"><a id="l00247" name="l00247"></a><span class="lineno">  247</span>                                       <a class="code hl_typedef" href="namespaceflow_1_1util.html#ac3e89a8a271b0ddc76ac2a0ce488dea4">Task_engine</a>* task_engine,</div>
<div class="line"><a id="l00248" name="l00248"></a><span class="lineno">  248</span>                                       Scheduled_task_handler&amp;&amp; task_body_moved)</div>
<div class="line"><a id="l00249" name="l00249"></a><span class="lineno">  249</span>{</div>
<div class="line"><a id="l00250" name="l00250"></a><span class="lineno">  250</span>  <span class="comment">/* The core object, Timer m_timer, has expires_at() and expires_after() available.  As a black box, perhaps it&#39;d</span></div>
<div class="line"><a id="l00251" name="l00251"></a><span class="lineno">  251</span><span class="comment">   * be best for us to call those respectively from schedule_task_at() and schedule_task_from_now().  However,</span></div>
<div class="line"><a id="l00252" name="l00252"></a><span class="lineno">  252</span><span class="comment">   * certain boost.asio docs suggest that ultimately Timer is built around the &quot;fire T period after now&quot; routine,</span></div>
<div class="line"><a id="l00253" name="l00253"></a><span class="lineno">  253</span><span class="comment">   * so it would ultimately just subtract Fine_clock::now() anyway even in expires_at().  So, for simpler code, we just</span></div>
<div class="line"><a id="l00254" name="l00254"></a><span class="lineno">  254</span><span class="comment">   * do that here and no longer worry about it subsequently.</span></div>
<div class="line"><a id="l00255" name="l00255"></a><span class="lineno">  255</span><span class="comment">   *</span></div>
<div class="line"><a id="l00256" name="l00256"></a><span class="lineno">  256</span><span class="comment">   * This is the reason for the `### Performance note ###` in our doc header. */</span></div>
<div class="line"><a id="l00257" name="l00257"></a><span class="lineno">  257</span>  <span class="keywordflow">return</span> schedule_task_from_now&lt;Scheduled_task_handler&gt;(logger_ptr,</div>
<div class="line"><a id="l00258" name="l00258"></a><span class="lineno">  258</span>                                                        at - Fine_clock::now(),</div>
<div class="line"><a id="l00259" name="l00259"></a><span class="lineno">  259</span>                                                        single_threaded, task_engine, std::move(task_body_moved));</div>
<div class="line"><a id="l00260" name="l00260"></a><span class="lineno">  260</span>}</div>
<div class="line"><a id="l00261" name="l00261"></a><span class="lineno">  261</span> </div>
<div class="line"><a id="l00262" name="l00262"></a><span class="lineno">  262</span>} <span class="comment">// namespace flow::util</span></div>
<div class="ttc" id="aclassboost_1_1system_1_1system__error_html"><div class="ttname"><a href="classboost_1_1system_1_1system__error.html">boost::system::system_error</a></div></div>
<div class="ttc" id="aclassflow_1_1log_1_1Logger_html"><div class="ttname"><a href="classflow_1_1log_1_1Logger.html">flow::log::Logger</a></div><div class="ttdoc">Interface that the user should implement, passing the implementing Logger into logging classes (Flow'...</div><div class="ttdef"><b>Definition:</b> <a href="log_8hpp_source.html#l01280">log.hpp:1284</a></div></div>
<div class="ttc" id="aclassflow_1_1util_1_1Unique__id__holder_html_a50489177a7731618ca130468c3872748"><div class="ttname"><a href="classflow_1_1util_1_1Unique__id__holder.html#a50489177a7731618ca130468c3872748">flow::util::Unique_id_holder::create_unique_id</a></div><div class="ttdeci">static id_t create_unique_id()</div><div class="ttdoc">Short-hand for Unique_id_holder().unique_id(); useful when all you want is the unique integer itself.</div><div class="ttdef"><b>Definition:</b> <a href="uniq__id__holder_8cpp_source.html#l00058">uniq_id_holder.cpp:58</a></div></div>
<div class="ttc" id="aerror_2error_8hpp_html_a019ee6e90802e444572dd78d312d6e23"><div class="ttname"><a href="error_2error_8hpp.html#a019ee6e90802e444572dd78d312d6e23">FLOW_ERROR_SYS_ERROR_LOG_WARNING</a></div><div class="ttdeci">#define FLOW_ERROR_SYS_ERROR_LOG_WARNING()</div><div class="ttdoc">Logs a warning about the (often errno-based or from a library) error code in sys_err_code.</div><div class="ttdef"><b>Definition:</b> <a href="error_2error_8hpp_source.html#l00269">error.hpp:269</a></div></div>
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<div class="ttc" id="alog_8hpp_html_ae4b5d4fdd2eb052615620879dd74af95"><div class="ttname"><a href="log_8hpp.html#ae4b5d4fdd2eb052615620879dd74af95">FLOW_LOG_SET_CONTEXT</a></div><div class="ttdeci">#define FLOW_LOG_SET_CONTEXT(ARG_logger_ptr, ARG_component_payload)</div><div class="ttdoc">For the rest of the block within which this macro is instantiated, causes all FLOW_LOG_....</div><div class="ttdef"><b>Definition:</b> <a href="log_8hpp_source.html#l00405">log.hpp:405</a></div></div>
<div class="ttc" id="alog_8hpp_html_affcf2e4c496ce3f42adf981669c623b8"><div class="ttname"><a href="log_8hpp.html#affcf2e4c496ce3f42adf981669c623b8">FLOW_LOG_TRACE</a></div><div class="ttdeci">#define FLOW_LOG_TRACE(ARG_stream_fragment)</div><div class="ttdoc">Logs a TRACE message into flow::log::Logger *get_logger() with flow::log::Component get_log_component...</div><div class="ttdef"><b>Definition:</b> <a href="log_8hpp_source.html#l00227">log.hpp:227</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html"><div class="ttname"><a href="namespaceflow_1_1util.html">flow::util</a></div><div class="ttdoc">Flow module containing miscellaneous general-use facilities that don't fit into any other Flow module...</div><div class="ttdef"><b>Definition:</b> <a href="basic__blob_8hpp_source.html#l00028">basic_blob.hpp:29</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_a5d2247b715da63e4b960909561b90ae7"><div class="ttname"><a href="namespaceflow_1_1util.html#a5d2247b715da63e4b960909561b90ae7">flow::util::Lock_guard</a></div><div class="ttdeci">boost::unique_lock&lt; Mutex &gt; Lock_guard</div><div class="ttdoc">Short-hand for advanced-capability RAII lock guard for any mutex, ensuring exclusive ownership of tha...</div><div class="ttdef"><b>Definition:</b> <a href="util__fwd_8hpp_source.html#l00265">util_fwd.hpp:265</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_a74d4a66fb00055be4e1bd6ee98e04667"><div class="ttname"><a href="namespaceflow_1_1util.html#a74d4a66fb00055be4e1bd6ee98e04667">flow::util::schedule_task_from_now</a></div><div class="ttdeci">Scheduled_task_handle schedule_task_from_now(log::Logger *logger_ptr, const Fine_duration &amp;from_now, bool single_threaded, Task_engine *task_engine, Scheduled_task_handler &amp;&amp;task_body_moved)</div><div class="ttdoc">Schedule the given function to execute in a certain amount of time: A handy wrapper around Timer (asi...</div><div class="ttdef"><b>Definition:</b> <a href="sched__task_8hpp_source.html#l00034">sched_task.hpp:34</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_aa0d10f5a906b3229f48979aa43e9ff7e"><div class="ttname"><a href="namespaceflow_1_1util.html#aa0d10f5a906b3229f48979aa43e9ff7e">flow::util::Scheduled_task_handle</a></div><div class="ttdeci">boost::shared_ptr&lt; Scheduled_task_handle_state &gt; Scheduled_task_handle</div><div class="ttdoc">Black-box type that represents a handle to a scheduled task as scheduled by schedule_task_at() or sch...</div><div class="ttdef"><b>Definition:</b> <a href="sched__task__fwd_8hpp_source.html#l00045">sched_task_fwd.hpp:45</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_aad8c8f7335eb892350dc386cb4be397e"><div class="ttname"><a href="namespaceflow_1_1util.html#aad8c8f7335eb892350dc386cb4be397e">flow::util::schedule_task_at</a></div><div class="ttdeci">Scheduled_task_handle schedule_task_at(log::Logger *logger_ptr, const Fine_time_pt &amp;at, bool single_threaded, Task_engine *task_engine, Scheduled_task_handler &amp;&amp;task_body_moved)</div><div class="ttdoc">Identical to schedule_task_from_now() except the time is specified in absolute terms.</div><div class="ttdef"><b>Definition:</b> <a href="sched__task_8hpp_source.html#l00245">sched_task.hpp:245</a></div></div>
<div class="ttc" id="anamespaceflow_1_1util_html_ac3e89a8a271b0ddc76ac2a0ce488dea4"><div class="ttname"><a href="namespaceflow_1_1util.html#ac3e89a8a271b0ddc76ac2a0ce488dea4">flow::util::Task_engine</a></div><div class="ttdeci">boost::asio::io_context Task_engine</div><div class="ttdoc">Short-hand for boost.asio event service, the central class of boost.asio.</div><div class="ttdef"><b>Definition:</b> <a href="util__fwd_8hpp_source.html#l00135">util_fwd.hpp:135</a></div></div>
<div class="ttc" id="anamespaceflow_html_a29eaaa9d0fac4ce87d8b969222dbed09"><div class="ttname"><a href="namespaceflow.html#a29eaaa9d0fac4ce87d8b969222dbed09">flow::Error_code</a></div><div class="ttdeci">boost::system::error_code Error_code</div><div class="ttdoc">Short-hand for a boost.system error code (which basically encapsulates an integer/enum error code and...</div><div class="ttdef"><b>Definition:</b> <a href="common_8hpp_source.html#l00508">common.hpp:508</a></div></div>
<div class="ttc" id="anamespaceflow_html_a48799f1263cdeedec125be51a3db2b79"><div class="ttname"><a href="namespaceflow.html#a48799f1263cdeedec125be51a3db2b79">flow::Fine_duration</a></div><div class="ttdeci">Fine_clock::duration Fine_duration</div><div class="ttdoc">A high-res time duration as computed from two Fine_time_pts.</div><div class="ttdef"><b>Definition:</b> <a href="common_8hpp_source.html#l00416">common.hpp:416</a></div></div>
<div class="ttc" id="anamespaceflow_html_a9d9cc2eeb10d398cff5591d446b763b8"><div class="ttname"><a href="namespaceflow.html#a9d9cc2eeb10d398cff5591d446b763b8">flow::Fine_time_pt</a></div><div class="ttdeci">Fine_clock::time_point Fine_time_pt</div><div class="ttdoc">A high-res time point as returned by Fine_clock::now() and suitable for precise time math in general.</div><div class="ttdef"><b>Definition:</b> <a href="common_8hpp_source.html#l00413">common.hpp:413</a></div></div>
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